Low-cement castable (LCC) is a high-performance refractory material with cement content ≤8%. Compared with ordinary refractory castables, it has the advantages of high density, excellent high-temperature strength, good thermal shock resistance, and long service life. Widely used in cement kilns, steel plant furnaces, boilers, and other high-temperature industrial scenarios. Below is a detailed introduction to its definition, working principle, key properties, applications, and selection guide.
Core Advantages of Low-Cement Castable:
Low Cement Content (≤8%)
High Density & High-Temperature Strength
Excellent Thermal Shock Resistance & Corrosion Resistance
Low-cement castable is a type of unshaped refractory material with calcium aluminate cement content controlled at 3-8% (lower than ordinary refractory castables with 20-30% cement content). According to ASTM standards, low-cement castable is defined by its CaO content ranging from 1.0% to 2.5%, which is a key indicator distinguishing it from ultra-low cement castables (CaO content 0.2%-1.0%) and ordinary refractory castables (CaO content >2.5%).
Composed of high-purity aggregates (high-alumina clinker, corundum, silicon carbide), ultra-fine powders (silica fume, alumina powder), and additives (dispersants, plasticizers), low-cement castable is formed by pouring and curing. After high-temperature sintering, it forms a dense structure with excellent high-temperature performance. Unlike traditional refractory castables, low-cement castable uses ultra-fine powders with chemical compositions similar to the main material to replace part or most of the calcium aluminate cement, resulting in a coexistence of hydraulic bonding and cohesive bonding, which is the fundamental reason for its superior performance. It is the core material for lining of high-temperature industrial equipment requiring high strength and long service life.
The excellent performance of low-cement castable is mainly derived from its unique composition and curing-sintering mechanism, which is quite different from the simple hydraulic bonding of ordinary cement castables:
Low cement content reduces the generation of low-melting phases at high temperatures. Excessive low-melting phases are the main cause of performance degradation of refractory materials in high-temperature environments, so reducing their content significantly improves the material’s high-temperature stability.
Ultra-fine powders (such as silica fume with a specific surface area of about 20m²/g, which is about 1/100 of the size of cement particles) fill the gaps between aggregates, greatly improving the compactness of the material. The appropriate dosage of silica fume is ≥3%, which can effectively enhance the strength of the castable while ensuring good refractory performance.
During curing and sintering, the cement hydrates and reacts with ultra-fine powders to form a stable ceramic bonding phase (such as mullite). This bonding phase has higher strength and thermal stability than the hydraulic bonding phase of ordinary cement, which is the key to the excellent high-temperature strength of low-cement castable.
The cohesive bonding mechanism plays a vital role: when ultra-fine silica powder mixes with water, it forms colloidal particles. These particles carry negative charges due to the dissociation of Si-OH groups. They then adsorb Al³+ and Ca²+ ions slowly dissolved during the hydrolysis of calcium aluminate, reducing the surface potential of the colloidal particles. When the adsorption reaches the “isoelectric point” (i.e., the colloidal particles are uncharged), agglomeration occurs to produce bonding. Subsequent drying completes the hardening process.
At high temperatures, the surface of the low-cement castable forms a dense protective layer, which can resist the erosion of slag, alkali metals, and corrosive gases, ensuring long-term stable operation of the industrial equipment lining.
The core properties of low-cement castable are significantly superior to ordinary refractory castables, especially in terms of high-temperature performance and compactness. The detailed parameters are as follows (test standard: ASTM C133/ASTM C1171):
|
Property Type |
Test Condition |
Parameter Range |
Advantage Explanation |
|---|---|---|---|
|
Bulk Density |
110℃, 24h drying |
2.5-2.8 g/cm³ |
High density, small porosity, strong resistance to slag penetration. The mixing water consumption is only 1/2 to 1/3 of that of ordinary refractory castables (about 4%-6%), which is the fundamental guarantee for high density. |
|
Flexural Strength |
110℃, 24h drying |
8-12 MPa |
Good early strength, not easy to crack during construction and curing, reducing construction risks. |
|
Flexural Strength |
1450℃, 3h sintering |
10-15 MPa |
High-temperature strength is stable, not easy to deform under long-term high-temperature operation, ensuring the structural integrity of the lining. |
|
Compressive Strength |
110℃, 24h drying |
60-80 MPa |
Strong bearing capacity, suitable for load-bearing parts of high-temperature equipment such as blast furnace boshes. |
|
Compressive Strength |
1450℃, 3h sintering |
70-90 MPa |
High-temperature compressive performance is excellent, long service life. Unlike ordinary castables whose strength decreases at medium temperatures, the strength of low-cement castables gradually increases with the increase of heat treatment temperature. |
|
Refractoriness |
ASTM C1171 |
≥1750℃ |
Adapt to high-temperature working conditions of industrial kilns such as cement rotary kilns and steel converters. |
|
Linear Change Rate |
1450℃, 3h sintering |
-0.5% ~ +0.3% |
Small volume change at high temperature, good structural stability, avoiding cracks caused by volume expansion and contraction. |
|
Thermal Shock Resistance |
1100℃ → water cooling |
≥25 times |
Resist frequent temperature changes, not easy to crack. Suitable for equipment with large temperature fluctuations such as waste incineration boilers. |
|
Thermal Conductivity |
350℃ |
1.5-2.0 W/(m·K) |
Good thermal conductivity, suitable for heat transfer parts. At the same time, the low porosity also helps to reduce heat loss. |
Low-cement castable is widely used in high-temperature industrial scenarios due to its excellent high-temperature performance, compact structure, and strong corrosion resistance. It is classified by industry, with detailed application information as follows (core focus on high-demand scenarios):
The cement industry is one of the largest application fields of low-cement castable. The working environment of cement kilns and related equipment is harsh, with high temperature, alkali corrosion, and slag erosion, which puts forward high requirements for refractory materials. Low-cement castable can effectively solve the problems of short service life and frequent maintenance of traditional refractory materials in cement kilns.
|
Application Parts |
Working Conditions |
Product Role |
Adapted Parameters |
Industry Value |
|---|---|---|---|---|
|
Cement rotary kiln lining、calciner、preheater cone |
High temperature (1500-1700℃)、alkali corrosion、slag erosion |
Lining protection、anti-corrosion & anti-scaling. Prevent the lining from being eroded by alkali metals and slag, and avoid scaling which affects the normal operation of the kiln. |
Alkali-resistant low-cement castable、refractoriness ≥1750℃、compressive strength ≥70MPa (1450℃)、CaO content ≤2.5% |
Extend kiln lining service life by 30%、reduce maintenance frequency from 4 times a year to 2 times、improve cement production efficiency by 15%、reduce annual maintenance cost by hundreds of thousands of US dollars. |
|
Kiln head cover、cooler lining |
High temperature (1200-1400℃)、thermal shock、dust erosion. Frequent temperature changes and dust impact easily cause lining damage. |
Thermal insulation & wear resistance. Protect the equipment shell from high temperature and reduce heat loss. |
Low-cement castable with thermal insulation performance、bulk density 2.5-2.6 g/cm³、thermal shock resistance ≥25 times |
Reduce heat loss by 20%、protect equipment shell、lower energy consumption、extend cooler service life by 25%. |
In the steel metallurgy industry, equipment such as steelmaking converters, blast furnaces, and heat treatment furnaces operate at ultra-high temperatures and are subjected to severe slag erosion and molten steel scouring. Low-cement castable, with its high high-temperature strength and corrosion resistance, has become the preferred refractory material for these key parts.
|
Application Parts |
Working Conditions |
Product Role |
Adapted Parameters |
Industry Value |
|---|---|---|---|---|
|
Steelmaking converter lining、blast furnace bosh、heat treatment furnace lining |
High temperature (1600-1800℃)、heavy slag erosion、frequent temperature changes. The lining is subjected to strong mechanical impact and chemical erosion. |
High-temperature wear resistance、corrosion resistance. Maintain the structural integrity of the furnace lining and ensure the normal progress of steelmaking. |
High-alumina low-cement castable、Al₂O₃ ≥80%、thermal shock resistance ≥30 times、refractoriness ≥1780℃ |
Extend furnace service life by 50%、reduce shutdown maintenance time by 40%、ensure stable steelmaking quality、reduce the loss caused by unplanned shutdown. |
|
Tundish、ladle lining |
High temperature (1500-1600℃)、molten steel erosion. The lining is in direct contact with molten steel, requiring high purity and corrosion resistance. |
Molten steel insulation、anti-erosion. Ensure the temperature stability of molten steel and prevent impurities from entering the molten steel. |
Low-cement castable with high purity、low impurity content (≤1%)、compressive strength ≥65MPa (1450℃) |
Ensure molten steel temperature stability、improve steel product qualification rate by 8%、reduce the consumption of refractory materials per ton of steel. |
With the development of the power industry, especially the popularization of waste incineration power generation, power plant boilers and waste incineration boilers face increasingly harsh working conditions. Low-cement castable, with its good thermal shock resistance and corrosion resistance, is widely used in the lining of key parts of boilers.
|
Application Parts |
Working Conditions |
Product Role |
Adapted Parameters |
Industry Value |
|---|---|---|---|---|
|
Power plant boiler water wall、superheater、reheater |
High temperature (1200-1500℃)、high pressure、flue gas corrosion. High pressure and corrosive flue gas easily cause damage to the boiler parts. |
High-temperature protection、anti-corrosion. Protect the key components of the boiler and ensure the safe operation of the boiler. |
Heat-resistant low-cement castable、compressive strength ≥60MPa (110℃)、good adhesion、corrosion resistance to flue gas |
Protect boiler key components、extend boiler service life by 30%、ensure safe operation of power plant、reduce the risk of boiler accidents. |
|
Waste incineration boiler lining |
High temperature (1000-1300℃)、complex waste corrosion、thermal shock. The composition of waste is complex, and the generated corrosive gases and ash have strong erosion on the lining. |
Corrosion resistance、thermal shock resistance. Adapt to the harsh working conditions of waste incineration and ensure the long-term operation of the boiler. |
Corrosion-resistant low-cement castable、thermal shock resistance ≥25 times、good resistance to acid and alkali corrosion |
Adapt to harsh working conditions of waste incineration、reduce maintenance costs by 40%、extend the service life of the waste incineration boiler by 25%. |
Chemical Industry: Application parts include chemical reactor lining、high-temperature pipeline、incinerator. Working Conditions: High temperature (1200-1500℃)、chemical corrosion (acid、alkali、salt). Adapted Product: Chemical-resistant low-cement castable. Role: Resist acid-base corrosion、ensure equipment safety、prevent leakage of chemical media. Industry Value: Extend the service life of chemical equipment、improve production safety、reduce maintenance costs.
Ceramic Industry: Application parts include ceramic tunnel kiln lining、sagger. Working Conditions: Stable high temperature (1400-1600℃)、long-term operation. Adapted Product: High-alumina low-cement castable. Role: High-temperature stability、ensure uniform kiln temperature、improve the quality of ceramic products. Industry Value: Extend the service life of the tunnel kiln、improve the qualification rate of ceramic products by 10%、reduce energy consumption.
Nonferrous Metallurgy Industry: Application parts include aluminum electrolysis cell lining、copper smelting furnace. Working Conditions: High temperature (1200-1500℃)、molten metal erosion. Adapted Product: High-purity low-cement castable. Role: Anti-erosion、extend equipment service life、prevent contamination of nonferrous metals. Industry Value: Reduce the consumption of refractory materials、improve the quality of nonferrous metal products、extend the service life of smelting equipment by 30%.
The selection of low-cement castable should be based on the working conditions of the application scenario (temperature、corrosion type、load-bearing requirements). The performance of low-cement castable is affected by many factors, such as ultra-fine powder type and dosage、calcium aluminate cement content、refractory aggregate、and water dosage. Therefore, scientific selection is crucial to ensure the service effect and reduce costs. The specific selection logic and recommendations are as follows:
|
Application Scenario |
Core Requirements |
Selection Key Points |
Recommended Product Type |
|---|---|---|---|
|
Cement kiln rotary kiln、calciner |
High temperature (≥1600℃)、alkali corrosion、slag erosion |
Refractoriness ≥1750℃、alkali resistance (low CaO content)、high compressive strength、good anti-scaling performance |
Alkali-resistant high-alumina low-cement castable (Al₂O₃ ≥75%) |
|
Steel converter、blast furnace |
Ultra-high temperature (≥1700℃)、heavy slag erosion、thermal shock |
High Al₂O₃ content、excellent thermal shock resistance、high density、strong corrosion resistance |
Corundum low-cement castable (Al₂O₃ ≥90%) |
|
Power plant boiler、waste incinerator |
High temperature (1200-1500℃)、corrosion、thermal shock |
Corrosion resistance (acid、alkali、flue gas)、good thermal shock resistance、stable strength at high temperature |
Heat-resistant corrosion-resistant low-cement castable |
|
Chemical reactor、high-temperature pipeline |
Chemical corrosion (acid/base)、high temperature (1200-1400℃) |
Low impurity content、strong chemical corrosion resistance、good compactness |
Chemical-resistant low-cement castable |
|
Load-bearing parts (blast furnace bosh、ladle) |
High compressive strength、high-temperature stability |
Compressive strength ≥80MPa (1450℃)、low linear change rate、good structural stability |
High-strength low-cement castable |
Selection Tips:
For ultra-high temperature scenarios (≥1800℃), it is recommended to choose corundum-based low-cement castable with higher purity. The high Al₂O₃ content can ensure excellent high-temperature stability and corrosion resistance.
For scenarios with strong alkali corrosion (such as cement kilns), pay attention to the alkali resistance index of the product and choose materials with low CaO content (≤2.0%). Excessive CaO will react with alkali metals to form low-melting phases, reducing the service life of the lining.
For emergency repair scenarios, you can choose fast-setting low-cement castable (initial setting time 30-60min) to shorten the construction period. At the same time, pay attention to the early strength performance of the product to ensure that it can meet the use requirements quickly.
The mixing water dosage of low-cement castable is strictly controlled (4%-6%). Excessive water will increase the porosity of the material and reduce its high-temperature performance. Therefore, it is necessary to choose products with good fluidity and match appropriate dispersants.
Low-cement castable has the characteristics of dense and high strength, which brings advantages to use but also troubles to baking. Improper baking is easy to cause spalling or cracking. Therefore, it is crucial to formulate a reasonable furnace baking curve and use excellent explosion-proof admixtures to ensure the smooth discharge of moisture in the castable without causing any side effects.
Not sure how to select the right low-cement castable for your scenario? Get Free Custom Scenario Adaptation Plan by providing your industry、application parts、and operating temperature.
Our low-cement castable adopts advanced production technology and strict quality control to ensure product performance stability. The whole production process is carried out in accordance with international standards, and every link is strictly monitored:
Raw material screening: Select high-purity aggregates (high-alumina clinker、corundum) and ultra-fine powders (silica fume、alumina powder) with impurity content ≤1%. The quality of raw materials is the foundation of product performance, so we have established a strict raw material inspection system to ensure that each batch of raw materials meets the requirements.
Precise proportioning: Use computer-controlled automatic proportioning equipment to ensure the accuracy of cement content (3-8%) and ultra-fine powder ratio. The proportioning error is controlled within ±0.5%, which effectively avoids performance fluctuations caused by inaccurate proportioning.
Mixing & homogenizing: Adopt high-speed mixing equipment to ensure uniform mixing of materials. The mixing time is strictly controlled according to the product type, ensuring that all components are fully integrated and the fluidity and uniformity of the castable are guaranteed.
Quality inspection: Implement three-step inspection (raw material inspection → process inspection → finished product inspection). For finished products, full indicators testing is carried out, including bulk density、compressive strength、flexural strength、refractoriness、and linear change rate. Only products that pass all tests can leave the factory.
Packaging & storage: Use moisture-proof packaging to avoid material deterioration during storage. Each package is marked with product information (type、batch number、production date、expiry date) to facilitate traceability and management.
Our low-cement castable has passed international authoritative certifications such as ISO 9001:2015、CE、ASTM、and SGS, which is a powerful guarantee for product quality. We have a professional quality inspection team and advanced testing equipment (high-temperature furnace、compressive strength tester、thermal shock resistance tester), which can conduct accurate testing of various performance indicators of low-cement castable.
We can provide detailed test reports (including density、strength、refractoriness、linear change rate) for each batch of products according to customer requirements, ensuring that customers can clearly understand the performance of the products they purchase. At the same time, we regularly carry out internal quality audits and technical upgrades to continuously improve the quality of our products and services.
Our low-cement castable has been exported to more than 50 countries and regions around the world, and has won wide recognition from customers in the cement、steel、power、and chemical industries. The following are typical overseas customer cases:
Case 1: Indonesian Cement Plant
Cooperation Content: Purchased 250 tons of alkali-resistant low-cement castable for rotary kiln lining;
Application Background: The original lining material of the customer’s cement kiln had a short service life (only 12 months) and required frequent maintenance, which seriously affected production efficiency;
Application Effect: After using our alkali-resistant low-cement castable, the service life of the kiln lining reached 18 months (30% longer than the original ordinary castable), and the annual maintenance cost was reduced by 450,000 US dollars;
Customer Feedback: “The low-cement castable has excellent high-temperature performance and alkali resistance, which has significantly improved the operating efficiency of our cement kiln. The after-sales technical support team provided professional furnace baking guidance, which ensured the smooth use of the product. We will continue to cooperate with this supplier.”
Case 2: Indian Steel Plant
Cooperation Content: Supplied 300 tons of corundum low-cement castable for converter lining;
Application Background: The customer’s steelmaking converter was facing the problem of severe slag erosion, and the lining needed to be replaced every 6 months, resulting in high production costs;
Application Effect: Our corundum low-cement castable effectively resisted high-temperature slag erosion, and the service life of the converter lining was extended by 50% (up to 9 months). At the same time, the stability of the lining also improved the quality of steelmaking;
Customer Feedback: “The product quality is stable, the high-temperature strength is excellent, and the after-sales technical support is professional. The technical team sent by the supplier conducted on-site construction guidance, which ensured the construction quality. We will continue to cooperate for a long time and have plans to expand the purchase volume next year.”
Q1: What is the difference between low-cement castable and ordinary refractory castable? A: The core difference is the cement content and bonding mechanism: low-cement castable has a cement content of 3-8% (CaO content 1.0%-2.5%), while ordinary castable is 20-30% (CaO content >2.5%). In terms of bonding mechanism, low-cement castable is a coexistence of hydraulic bonding and cohesive bonding, while ordinary castable is mainly hydraulic bonding. In terms of performance, low-cement castable has higher density、better high-temperature strength、and longer service life, but the cost is slightly higher. It is suitable for high-demand high-temperature scenarios, while ordinary castable is suitable for low-demand scenarios with lower temperature and less corrosion.
Q2: What is the difference between low-cement castable and ultra-low cement castable? A: The main difference is the cement content and CaO content: ultra-low cement castable has a cement content of 2.5-5% (CaO content 0.2%-1.0%), which is lower than low-cement castable. In terms of bonding mechanism, ultra-low cement castable is mainly cohesive bonding, while low-cement castable is a coexistence of hydraulic bonding and cohesive bonding. Ultra-low cement castable has better high-temperature performance but higher requirements for construction and curing (strict control of water dosage and curing temperature), and the cost is higher. Low-cement castable has better cost performance and wider applicability, which is the most widely used type of high-performance unshaped refractory material.
Q3: Do you provide customized low-cement castable according to specific working conditions? A: Yes! We can customize the composition (Al₂O₃ content、cement content、CaO content), performance parameters (refractoriness、strength、thermal shock resistance), and packaging according to your application scenario、operating temperature、corrosion type、and construction requirements. For example, for ultra-high temperature scenarios, we can increase the Al₂O₃ content to improve refractory performance; for strongly corrosive scenarios, we can adjust the type of ultra-fine powder to enhance corrosion resistance. MOQ for customization: 100 tons.
Q4: What are the payment terms and delivery time for bulk low-cement castable? A: Payment terms: T/T (30% deposit, 70% against B/L), L/C is acceptable. For long-term cooperative customers, we can provide more favorable payment terms. Delivery time: 7-15 working days for standard products, 20-30 working days for customized products. We can arrange door-to-door delivery through international logistics (sea、air) according to customer requirements, and provide complete customs clearance documents (commercial invoice、packing list、bill of lading、certificate of origin、certification documents) to ensure smooth customs clearance.
Q5: Do you provide technical support for construction and installation? A: Yes! We have a professional technical team with rich experience in the construction and application of low-cement castable. We can provide: 1. Detailed construction guidance manuals (including water dosage、mixing method、pouring process、curing requirements、furnace baking curve); 2. On-site installation guidance (dispatching technical engineers to the customer’s construction site to guide the construction); 3. Post-installation debugging services (testing the lining quality and providing optimization suggestions). Technical engineers can be dispatched overseas if needed.
Q6: How to store low-cement castable correctly? A: Low-cement castable should be stored in a dry、ventilated、and moisture-proof warehouse, avoiding direct sunlight and rain. The storage temperature should be between 5℃ and 35℃, and the shelf life is 6 months from the production date. During storage, it should be placed away from heat sources and corrosive substances. After opening the package, it should be used up as soon as possible (within 24 hours) to avoid moisture absorption and agglomeration affecting performance.
White corundum castable is a high-quality high-temperature refractory material with high-purity alumina powder as the main raw material.
High aluminum castable refers to a refractory castable with Al2O3 content greater than 48%.
Service Temp 800-1800℃ | ASTM/ISO Certified | Custom Formulations | Factory Direct Supply ① High Temp Stability (800-1800℃ Long-Term Service) ② Excellent Flowability (No Vibration Needed for Casting) ③ Strong Bonding & Wear Resistance (Compressive Strength ≥80MPa) ④ Fast Setting (24h Initial Setting, 72h Demolding)
Silicon carbide castable is an amorphous refractory material with silicon carbide as the main component.
Corundum mullite castable is a high-quality high-performance refractory material with high thermal conductivity, insulation, good chemical stability and resistance to reducing agents.
